Traditionally, wood products have been a primary source of materials for use in construction. However, wood products are becoming increasingly scarce due to the harvesting of trees at ever faster rates and the rather limited rate at which timber resources can be replenished. Also, environmental concerns and environmental regulations directed to conservation or preservation of forests tend to restrict the availability of wood products. With diminishing availability of timber resources, wood products are becoming increasingly expensive. There is, therefore, a substantial need for long-lasting substitute construction materials that can lessen the need to harvest timber resources.
One approach to addressing the above need is to provide a substitute replacement product made of plastic, rather than wood. However, the replacement or substitute product needs to be stable, rigid, and relatively inexpensive. It also needs to be easily fabricated and used in the field.
U.S. Pat. No. 5,253,458 describes a simulated log made from a cast polyvinylchloride (PVC) pipe, selectively filled with a hard cast foam or a bead type foam. Said patent further describes that the cast PVC pipe is first manufactured and then subsequently filled with the foam filler. This type of manufacturing tends to require excessive numbers of manufacturing operations, and at substantial cost.
Accordingly, it can be seen that there is yet a need in the art for a process of manufacturing foam-filled extruded plastic products, such as a replacement for traditional wood products, wherein the process should provide a strong finished product at minimal cost and with a minimal number of manufacturing steps. It is to the provision of such a process that the present invention is primarily directed.